Overview of Post Processing Framework¶

Overview¶

OpenMW supports a moddable post process framework for creating and controlling screenspace effects. This is integrated into OpenMW’s Lua API, see reference for details.

Basic concepts¶

Pass: Describes a single shader invocation pass. Currently only pixel (also known as fragment) shaders are supported.
Technique/Shader: An ordered list of passes, techniques will encompass a single effect like bloom or SSAO. Technique is interchangable with shader.

Installing and Activating¶

Shaders are managed through the virtual file system, simply install the associated archive or folder as described in mod-install. Shaders must be in the Shaders directory to be discoverable. A shader can be activated in one of two ways:

Adding the shaders filename (without its extension) to the end of the chain list in settings.cfg.
Using the in game post processor HUD, which can be activated with the F2 key by default. This is the recommended method as manual editing can be error prone.

Localization¶

Output text (e.g. shader description) can use the #{ContextName:Key} tags. In this case OpenMW replaces it for value of Key key from the Data Files\L10n\ContextName\used_language.yaml file.

Hot Reloading¶

It is possible to modify a shader without restarting OpenMW, hot reloading can be enabled by using the lua command debug.setShaderHotReloadEnabled(true). Whenever a file is modified and saved, the shader will automatically reload in game. This allows shaders to be written in a text editor you are comfortable with. The only restriction is that the VFS is not aware of new files or changes in non-shader files, so new shaders and localization strings can not be used.